Physiological Smolt Characteristics of Anadromous and Non-anadromous Brook Trout (Salvelinus fontinalis) and Atlantic Salmon (Salmo salar)

1985 ◽  
Vol 42 (3) ◽  
pp. 529-538 ◽  
Author(s):  
Stephen D. McCormick ◽  
Robert J. Naiman ◽  
Ellyn T. Montgomery
Keyword(s):  
Moisture Content ◽  
Atlantic Salmon ◽  
Atpase Activity ◽  
Salmo Salar ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Salt Water ◽  
Physiological Factors ◽  
Low Salinity ◽  
Atlantic Salmon Salmo Salar

Anadromous brook trout, Salvelinus fontinalis, of rivière à la Truite, Quebec, were examined for physiological changes associated with smoltification, and compared with non-anadromous brook trout from the adjacent Matamek River. There were no statistical differences in plasma thyroxine concentration, gill Na+, K+-ATPase activity, hematocrit, or osmoregulatory ability between the populations. Moisture content was different between the populations, but both had the same pattern of declining moisture content as summer progressed. Silver coloration of brook trout in rivière à la Truite was associated with larger fish and higher gill Na+, K+-ATPase activity, but not with changes in plasma thyroxine concentrations, moisture content, hematocrit, or condition factor. Brook trout at high-salinity estuarine sites had greater gill Na+, K+-ATPase activity and hypoosmoregulatory ability than those from low-salinity sites. Silvering of Atlantic salmon (Salmo salar) in rivière à la Truite was associated with larger fish, higher gill Na+, K+-ATPase activity, and higher plasma thyroxine. Gill Na+, K+-ATPase activity of highly silvered freshwater Atlantic salmon was greater than that of highly silvered brook trout. Estuarine Atlantic salmon had significantly higher plasma thyroxine concentration and gill Na+, K+-ATPase activity than estuarine brook trout. Based on these physiological factors, we conclude that smoltification is undeveloped in brook trout and that estuarine residence is important for salt water acclimation and eventual seaward migration.

Rainbow trout (Oncorhynchus mykiss) habitat overlap with wild Atlantic salmon (Salmo salar) and brook trout (Salvelinus fontinalis) in natural streams: do habitat and landscape factors override competitive interactions?

2018 ◽  
Vol 75 (11) ◽  
pp. 1949-1959
Author(s):  
Scott D. Roloson ◽  
Kyle M. Knysh ◽  
Michael R.S. Coffin ◽  
Karen L. Gormley ◽  
Christina C. Pater ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Atlantic Salmon ◽  
Oncorhynchus Mykiss ◽  
Salmo Salar ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Habitat Overlap ◽  
Atlantic Salmon Salmo Salar ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Natural Streams

The purpose of this study was to update rainbow trout (Oncorhynchus mykiss) invasion status, delineate factors that increase the invasion probability, and quantify habitat overlap between invasive rainbow trout and native Atlantic salmon (Salmo salar) and brook trout (Salvelinus fontinalis) on Prince Edward Island, Canada. Analysis of landscape-level variables in 26 watersheds (14 with and 12 without rainbow trout) demonstrated that watershed slope, percent agricultural land use, and distance to the nearest rainbow trout population significantly increased the probability of rainbow trout establishment. Two independent reach-level fish community surveys were conducted by electrofishing in combination with habitat surveys. Reaches with rainbow trout had higher stream slope, Atlantic salmon were found in wider reaches with larger substrate, and brook trout were typically dominant in headwater reaches with finer substrate. Findings at multiple ecological scales illustrated that rainbow trout invasion success is positively influenced by the presence of high-slope habitat. Habitat separation of the three salmonid species indicates that competition with introduced rainbow trout may not be the most significant threat to native salmonid populations.

Parr–Smolt Transformation of Yearling Atlantic Salmon (Salmo salar) at Several Rearing Temperatures

1981 ◽  
Vol 38 (10) ◽  
pp. 1189-1198 ◽  
Author(s):  
C. E. Johnston ◽  
R. L. Saunders
Keyword(s):  
Atlantic Salmon ◽  
Atpase Activity ◽  
Salmo Salar ◽  
Salinity Tolerance ◽  
Elevated Temperatures ◽  
Salt Water ◽  
Effect Of Temperature ◽  
Atlantic Salmon Salmo Salar ◽  
Thermal Effluent ◽  
Thermal Regimes

Six different rearing conditions were used to study the effect of temperature on seasonal changes in growth, condition factor, body silvering, body moisture and lipid content, salinity tolerance, and gill Na–K-ATPase activities of laboratory and pond-reared yearling Atlantic salmon (Salmo salar). Growth during the winter was greatest at the highest rearing temperature (16 °C) whereas those under simulated natural conditions grew slowest. Increasing temperatures in the spring stimulated growth more than constant temperature. Based on increased salinity tolerance, elevated ATPase activity, and growth in salt water, smolt development proceeded at all temperatures up to 16 °C. More smolts were produced in the high thermal regimes resulting in the best growth and the largest proportion of fish reaching smolt size. Unlike some Pacific salmonids, Atlantic salmon develop smolt status at temperatures as high as 16 °C. Yearling smolts can be produced at elevated temperatures and the use of thermal effluents for this purpose is promising.Key words: smoltification, smolt criteria, salinity tolerance, ATPase activity, rearing temperatures, elevated thermal regimes, thermal effluent, Salmo salar

Effects of Two Insecticides on the Vulnerability of Atlantic Salmon (Salmo salar) Parr to Brook Trout (Salvelinus fontinalis) Predation

1972 ◽  
Vol 29 (1) ◽  
pp. 27-29 ◽  
Author(s):  
C. T. Hatfield ◽  
J. M. Anderson
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Learning Ability ◽  
Laboratory Work ◽  
Organophosphate Insecticide ◽  
Safe Haven ◽  
Noticeable Effect ◽  
Atlantic Salmon Salmo Salar

The experiments were conducted in large outdoor concrete pools in which the salmon had access to a safe haven. After exposure for 24 hr to 1.0 ppm of the organophosphate insecticide, Sumithion, Atlantic salmon (Salmo salar) parr were more vulnerable than unexposed fish to prédation by large brook trout (Salvelinus fontinalis). Sumithion at 0.1 ppm, and DDT at 0.07 ppm, had no noticeable effect. The results, particularly for Sumithion, correlate well with previous laboratory work on the effect of insecticides on the learning ability of salmon.

Interactions of Atlantic salmon (Salmo salar) and trout (Salvelinus fontinalis and Oncorhynchus mykiss) in Vermont tributaries of the Connecticut River

2003 ◽  
Vol 60 (3) ◽  
pp. 279-285 ◽  
Author(s):  
Matthew J Raffenberg ◽  
Donna L Parrish
Keyword(s):  
Atlantic Salmon ◽  
Oncorhynchus Mykiss ◽  
Salmo Salar ◽  
Brook Trout ◽  
Life Histories ◽  
Salvelinus Fontinalis ◽  
Multiple Scales ◽  
Connecticut River ◽  
Growth And Survival ◽  
Atlantic Salmon Salmo Salar

Competitive interactions among stream salmonids in resource-limited environments have been linked to reduced success for many species. Few studies have focused on interactions at scales larger than individual fish or stream reach. We chose to focus our study on these larger scales to provide information for managing species that have complex life histories transcending multiple scales. Our objective was to explore age-0 Atlantic salmon (Salmo salar) growth and survival in relation to trout abundance (introduced rainbow (Oncorhynchus mykiss) and native brook (Salvelinus fontinalis) trout) and prey resources at 24 stream reaches across two Vermont watersheds that flow into the Connecticut River. Simple linear and multilinear regressions were conducted on response and predictor variables related to fish and invertebrate prey. Age-0 Atlantic salmon survival was greatest at the site with highest trout abundance; however, no linear relationships to trout abundance were detected possibly because Atlantic salmon growth and survival were highly variable across sites. In contrast, a positive significant multivariate relationship was identified among age-0 Atlantic salmon survival, the abundance of age-1+ brook trout (i.e., 100–130 mm), and benthic prey abundance. These results suggest that stocking streams based on trout abundance may not increase Atlantic salmon growth and survival during the first summer of life.

Fyke Net Catches as Indices of the Abundance of Brook Trout, Salvelinus fontinalis, and Atlantic Salmon, Salmo salar

1984 ◽  
Vol 41 (2) ◽  
pp. 377-380 ◽  
Author(s):  
P. M. Ryan
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Relative Abundance ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
Catch Per Unit Effort ◽  
Small Lakes ◽  
Population Densities ◽  
Atlantic Salmon Salmo Salar ◽  
Fyke Nets

The catch per unit effort (CPUE) data of brook trout (Salvelinus fontinalis) and Atlantic salmon (Salmo salar) in fyke nets set in two small lakes in central Newfoundland were compared with population densities estimated with Schnabel multiple mark–recapture experiments each spring and fall from 1978 to 1982. The catchability of brook trout did not differ significantly between lakes or seasons, and CPUE was an index of the relative abundance of trout within and between lakes. In contrast, the catchability of Atlantic salmon differed greatly between lakes and varied seasonally, being greater in the spring but less in the fall than the catchability of brook trout. Comparisons of relative salmon abundance between lakes or of the relative abundance of brook trout to Atlantic salmon within or between lakes require a correction for seasonal differences in the catchability of salmon.

Changes in Gill ATPase Activity and Smolt Status of Atlantic Salmon (Salmo salar)

1978 ◽  
Vol 35 (12) ◽  
pp. 1542-1546 ◽  
Author(s):  
Richard L. Saunders ◽  
Eugene B. Henderson
Keyword(s):  
Moisture Content ◽  
Atlantic Salmon ◽  
Atpase Activity ◽  
Salmo Salar ◽  
Salinity Tolerance ◽  
Atlantic Salmon Salmo Salar ◽  
Photoperiod Regime ◽  
Natural Photoperiod ◽  
Salmon Smolt ◽  
Photoperiod Manipulation

Gill Na+K+-activated ATPase activity increased during winter–spring in Atlantic salmon (Salmo salar) held at 10 °C and subjected to simulated natural or reciprocal (light/dark ratio opposite that of natural) photoperiods. ATPase activity increased earlier and was greater under the reciprocal than under the natural photoperiod regime. Body lipid decreased and moisture content increased sooner and more sharply in reciprocal than in natural photoperiod fish. Salinity tolerance (to 40‰) increased between March and April. Exposure to 40‰ salinity for periods up to 14 d gave marked increases in ATPase activity over levels measured in freshwater. Gill ATPase activity is a sensitive indicator of the ability of Atlantic salmon to osmoregulate in seawater. Together with lipid-moisture content, tolerance to high salinity, and migratory behavior, gill ATPase activity provides a valid indication of smolt readiness to migrate to sea. Key words: smolt criteria, photoperiod manipulation, Atlantic salmon, smolt physiology, salinity tolerance, osmoregulation

Selection by Brook Trout (Salvelinus fontinalis) and Juvenile Atlantic Salmon (Salmo salar) of Shade Related to Water Depth

1975 ◽  
Vol 32 (9) ◽  
pp. 1652-1656 ◽  
Author(s):  
R. John Gibson ◽  
G. Power
Keyword(s):  
Atlantic Salmon ◽  
Salmo Salar ◽  
Water Depth ◽  
Brook Trout ◽  
Salvelinus Fontinalis ◽  
The Other ◽  
Atlantic Salmon Salmo Salar ◽  
Juvenile Atlantic Salmon ◽  
Selection For ◽  
Salmon Parr

Salmon parr and small brook trout were observed in two stream tanks providing choices of cover. One tank was shallow (24–29 cm) and the other deep (43–50 cm). In the shallow tank brook trout occurred most frequently in shade. When salmon were the sole species, they were most frequently in shade, but were mostly away from shade in the presence of trout. This selection for shade was not evident by either species in the deep tank.

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